In reading about
the naming of the 12 Greek constellations (that comprise the 12 Signs of the
Zodiac in astrology), there are likely to be a few surprises. This holds true
even for those who "think" they already know the mythology behind
the naming of the constellations.

Also
when reading up on the naming of the 12 Greek constellations that comprise
the Zodiac, you're likely to be disappointed.
The various reasons for their naming are often going to be rather short and
sweet.

And,
finally, I hate to be the one to break it to you, but you'll often discover
that there is
often no single, definitive, absolute, "this
is it" answer for the Greek/Roman mythology behind the naming of
the 12 constellations contained in the Zodiac. Like anything concerning
ancient
Greek/Roman mythology, there will be differing variants, stories, and/or
legends.

The History
Behind Their Naming

The naming of
the constellations by the ancient Greeks most likely occurred sometime between
the 6th - 5th centuries B.C. However, the first satisfactory evidence of an
extensive set of Greek constellations existing comes from the 4th century
B.C. astronomer Eudoxus (390 – 340 B.C.). The works of Eudoxus are lost,
but are contained in the writings of another Greek, Aratus of Soli (315 –
245 B.C.). Aratus’ poetry "Phaenomena" provides a complete
guide to the constellations known to the ancient Greeks as laid down by Eudoxus.

Eudoxus had allegedly
learned about the constellations from priests in Egypt and then introduced
them to Greece. It's appears more likely, however, that the cosmological idea
of naming the constellations was appropriated from the Greek's neighbors the
Babylonians and Sumerians. Upon the Greeks "borrowing" the constellations
(and utilizing a few of the same figures and symbols) - they, then, went about
devising many of their own unique names and explanations as to how all the
different animals and people had gotten into the sky.

Originally
48

The ancient Greeks
originally gave us 48 "classical" constellations. Since then, more
and more constellations have been added - and today there are now a total
of 88.

The Imaginal
12 Sectors of the Zodiac

The Babylonians
and the Egyptians had also previously founded the cosmological concept
that
each year the Sun passed through divisions or sectors in the sky that were
located on an imaginary circle called the "ecliptic." It is
believed that the ancient, imaginal, and archetypal concept of a "world
soul"
ruled by divisions or sectors came first - then, later, (based on these preexisting
imaginal divisions) came the naming of the actual constellations in the
sky.
The Greeks also borrowed this idea from their neighbors.

The imaginary
"ecliptic" 12 sector circle of the Sun's path through the sky and
based on the changing seasons constructed by the Greeks (and later adopted
by the Romans) - is today commonly known as the 12 Signs of the Zodiac.